1. Field of the Invention
The present invention relates to a transit device of the kind defined in the preamble of claim 1.
Thus, the invention is concerned with a transit device which sealingly shields a wall opening through which one or more lines extend.
By line is meant an elongate object, such as a cable, a pipe, tubing or the like.
2. Description of Prior Art
Known transit devices generally include a clamping frame sealingly connected to a wall around a wall opening.
The clamping frame receives elastic blocks which together substantially fill-out the frame. At least one block has at least one through-penetrating channel and is divided to enable the channel to be exposed and therewith allow the block to be opened and fitted to the line.
The channel is normally shielded initially by a plug that fits into the channel. The frame also seals against the blocks, when said blocks fill-out the flame and when the frame is tensioned or tightened to compress the blocks and therewith eliminate any gaps between and within the blocks.
A block of this kind known in practice (WO 01/28057) is comprised, in connection with the channel, of radially, mutually sequential separable layers of material. By tearing or peeling off one or more of these layers, the channel can be made correspondingly larger so as to fit the outer diameter of the line concerned.
One drawback with this known solution is that the line-adapted block does not stay on the line prior to or subsequent to fitting the block in the clamping frame. If the line-adapted block goes astray among other blocks, the block can be considered to be lost, therewith necessitating the arrangement of a fresh block if the cable is to be sealingly connected in the transit.
It is also known that the line can be wrapped in a band of rectangular cross-sectional profile, wherewith numerous turns of the band are wound around the line in tight axial abutment with each other to form a bush, whereafter the thus formed bush is received sealingly in a through-penetrating channel in the divided block. However, it is necessary in principle to have available a band for each line dimension, or it is necessary to provide blocks that include a large number of different channel diameters. The line wrapping technique is labour consuming.
Divided blocks whose channel defining sides are formed by tearing or peeling away layers (WO 01/28057) or adding layers (U.S. Des. Pat. No. 401223), have certain advantages; the block can be readily adapted to lines of different diameters by peeling off or adding layers, the blocks have a standard outer diameter which is well adapted to respective clamping frames and when the adapted block is fitted to the cable an operator is able to see whether or not gaps are present between the blocks or between the cable and the channel walls of the block, prior to tightening the frame.
DE 4028570 A teaches a transit device comprising separate bushes that have an axial slot through the wall, wherein the bush wall is comprised of concentric layers that can be torn loose from one another so as to adapt the through-penetrating channel of the bush to the size of the cable concerned.